Compressor-valve.



cl w. VOLLMANN. CO'M PRESSOR VALVE.

' APPLICATION FILED JUNEZI, 1916.

1,258,167. Patented Mam-5,1918:

W1 95:25: I CIARLW-VOILMANN' MW #4347 v P r omey CARL WILHEL'M VOLLMANN, OF MONTREAL, QIlEBEC, CANADA.

COMPRESSOR-VALVE.

Specification 01' Letters Patent.

Application filed June 21, 1916. Serial uo.'1o5,o41.

I To all whom it may concern:

Be it known that I, CARL W. VOLLMANN, of the city of Montreal, Province of Quebec, Dominion of Canada, have invented certain new and useful Improvements in Compressor-Valves; and I do hereby declare that the following is a full, clear, and exact description thereof.

' My invention relates particularly to the suction and delivery or discharge valves of ammonia compressors and has for its object to provide valves of this nature embodying shockabsorbers adapted to offer a gradu ally increasing resistance as the pistons of the valves reach the ends of their strokes.

The invention may be said briefly to conslst of a valve proper the stem of which has at the opposite end to the valve proper a piston the stroke of which is cushioned by'a shock absorber consisting-of a vent or port in the cylinder for the piston and adapted to effect communication between the space within the cylinder and the surrounding space continuously during the major portion of the stroke, such vent or port being gradually reduced in capacity by the piston thus oifering an increasing resistance to the piston as it advances until finally the maximum resistance'stops the movement of the piston. The effect is that the first rapid initial movement of the piston is secured which is gradually reduced and the shock completely absorbed without any jar to the valve parts.

, For full comprehension, however, of my invention reference must be had to the accompanying drawings forming a part of this specification in which similar reference characters indicate the same parts and wherein:

Figure l is an axial vertical sectional view of an ammonia compressor provided with.

valves constructed according to my inven-. tion;

Figs. 2 and 3 are axial sectional viewsof my. improved suction and delivery or discharge valves; and' i Fig. 4 is a detail elevation of the shockabsorber end of the delivery 'or discharge valve, illustrating a modification.

The compressor is of the type com ris ng cylinder 6, piston 0, and the cyl1nder av1n a suction and delivery or discharge valve and e, respectively, at each end. During operation the stroke of the piston in one di-.

rection opens the suction valve and closes the discharge valve behind and opens the delivery or discharge valve and closes the suction valve in advance of it, and as the strokes of the piston are comparatively rapid the movement of the valves are correspondingly rapid and the shocks of their movement are so severe that they would be damaged and eventually destroyed if cushions were not provided. I

The cushion I have devised to absorb the shocks comprises a piston formed integrally with the valve stem and reciprocating in a cyllnder the interior of which has communication with the exterior, and such c0m-' :InllIHCfitlOIl is reduced by the piston as it advances. The valve proper is indicated at f,

the valve stem at g, the, piston at h and the cylinder in which the piston travels at 2',

" this cylinder being closed by a cylinder head j. The vent or port eifecting communication between the interior and exterior of this cylinder may consist of either a series of holes k, I0, k is", k ai'ranged preferably in axial alinement as shovsin in. Figs. 2 and 3,

Patented Mar. 5, 1918.

or'the communication may be effected by a I narrow slit m as shown in Fig. 4.

This se l ries of holes or the slit preferably extends from within a short distance of one end of the cylinder to within a short distance of the opposite end.

I. have described my'invention with relation to the delivery or discharge valve although, as illustrated in Fig. ,2, it is equally applicable to the suction valve; and the modification may be applied to :one as well as the other.-

Operation.

I will describe the operation of the delivery or discharge valve.

In the operation of my improved compressor-valve the pressure in advance of the valve-piston through the ports 7:, k, and k instantaneously equals the pressure exerted on the valve and as the piston advances it first cuts 01f the hole is, continued advancement cuts oil the hole 70 and finally hole is thus imprisoning a body of gas between the valve-piston and the cylinder head 9' and this gaseous body is compressed until its resistance equals the force of the piston and gradually brings it to a stop., The

' effect is that the resistance to the opening of mitting it to open rapidly then as the holes are cut nfi the resistance increases until the valveopening has reached its .full capacity when the last hole is closed thus causing the resistance to increase sufficiently to bring the valve to a stop Without shock. The effect of the series vof holes is that the resistance is increased by definite steps whereas the increase of resistance with the slit is uniformly progressive and although I prefer to use a series of holes I wish it to be understood that both specific forms come within the spirit of my invention. I

What I claim is as follows: i

1. In a compressor valve mechanism, the combination of a cylinder of comparatively small diameter having a longitudinal series of ports therein, a, valve-stem, one'end of which projects into the cylinder, a piston located in the cylinder and mounted on the end of the valve-stem, said piston being con structed and arranged to simultaneously cover a plurality of said ports; a valve proper located at the opposite end of the valve-stem, and a helical spring encircling the valve-stem and being located between the piston and valve proper and constructed and I I arranged to yieldingly mainta n the valve in closed position.

2. In a compressor valve mechanism, the combination of a casing having an extension of reduced diameter at one end thereof, and an opening in the opposite end thereof,

a valve controlling the opening, a cylinder located within said extension, a piston within the cylinder, a longitudinal series of ports in the cylinder constructed and arranged to ofi'er increasing resistance to the movement of the piston therein, a valve-stem located within the casing and having the piston and valve mounted upon its opposite ends re- CARL WILHELM VOLLMANN.

Witnesses:

WILLIAM Hnwn'rson, Gonuon G. CooKn. 

